Credit score ruined wrongfully- contract taken *****ulent

Someone at MTN took a contract on my behalf, I don’t know how they did it. I received messages and I’ve sent the ***** department an email and even called but they said there was nothing on the system indicating any sim swap. First debit order went through and I didn’t notice it, I only notice on the second one and had to reverse it. Now my credit score is ruined because of all this *****ulent ****.